T4 replication helicase (gp41) and polymerase (gp43) can be assembled onto a loading site located near the end of a long double-stranded DNA template in the presence of a macro-molecular crowding agent, and that this coupled “two-protein” system can carry out ATP-dependent strand displacement DNA synthesis at physiological rates (400 to 500 bp per sec) and with high processivity in the absence of other T4 DNA replication proteins.

Description:
T4 replication helicase (gp41) and polymerase (gp43) can be assembled onto a loading site located near the end of a long double-stranded DNA template in the presence of a macro-molecular crowding agent. This coupled “two-protein” system can carry out ATP-dependent strand displacement DNA synthesis at physiological rates (400 to 500 bp per sec), with high processivity in the absence of other T4 DNA replication proteins.

Source:
An enzyme from the gene of the bacteriophage T4 phage.

Application:
DNA helicase is an enzyme that aids in DNA synthesis by 'unzipping' the two strands of a DNA helix so that DNA polymerase can access the DNA to add nucleotides and effect copying.